1. Field of the Invention
The present invention relates to an expansive composition for an electric rock destruction, and in particular to an expansive cell composition for an electric rock destruction capable of enhancing a destructing force against rocks based on a stable expansion by a high temperature and impact wave energy generated in such a manner that a compound such as metallic salt and metallic powder that are source of oxygen instantly discharges a high current with respect to a metallic wire.
2. Description of the Background Art
Generally, in a chemical and explosive used for rock destruction in a civil construction, a compound therein is designed to chemically react by a small heat impact. At the time when a chemical reaction occurs, a large scale of gas expansion occurs for thereby destructing an object.
However, the above chemical and explosive are very unstable, so that they may be exploded by a very small impact and friction and furthermore an instant expansion reaction may be easily performed by heat. Therefore, when handling an instant expansion material such as explosive or chemicals, a very careful attention is needed. In the industry, a certain controllable explosive material has been urgently needed so that it is very stable for storage, and a desired large expansive force or a desired expansive force is obtained for explosion.
As the above explosive material, according to the Korean patent registration No. 213,577, an instant expansion metallic compound is developed. This compound is fabricated in such a manner that a metallic nitrate, a metallic powder capable of increasing a volume wherein it is oxidized by the metallic nitrate and is heated, and a reaction accelerator capable of accelerating an oxidation reaction of a metallic powder with the metallic nitrate. The above patent has advantages that a noise is small, and broken pieces do not fly away. However, in the above patent, the fabricated expansion agent is very weak to moisture, so that it is easily changed in quality. Since the reaction does not occur well after the change in quality, it is needed to supply a higher voltage using a power supply unit. In addition, an intensive electricity control technique is needed due to difficult handling, and there are always possible dangers. In view of the effects of rock destruction, workability and economic advantages are very low. In order to overcome the above problems, according to the Korean patent laid-open No. 2003-6083, an instant expansion material formed of a compound of a non-nitric acid metallic salt and metallic powder is developed. It is possible to significantly decrease noise, vibration and fly of broken pieces by decreasing the expanding force. In addition, the above method relates to an expansion agent fabrication method adapting a Thermit welding reaction used in an industrial field. In this case, a rock destruction work is possible under a negative pressure condition of rocks using a special stemming material. In addition, a certain object such as rocks is destructed based on a vaporization expansion method using a high temperature generating during a reaction of a metallic salt and a metallic powder. However, the above method is made without fully understanding a negative pressure generation condition and destruction condition (Fracture-ability class) of rocks, so that it is impossible to actually adapt the above method to an industrial field.
Generally, rocks have various kinds and sizes of non-continuities. Namely, there are non-continuities such as joint and cleavage and are further schistosity and bedding plane that occur at an initial step of formation of rocks. In addition, there are further non-continuities such as fault and fracture zone that are connected with a large scale of geology structure. Therefore, with the above features, rocks have mechanical heterogeneous and anisotropic structures. Therefore, in the case of the instant expansion metallic compound formed of a compound of a non-nitrate metallic salt and metallic powder, it can be very limitedly adapted with respect to intact rocks having homogeneous as well as isotropic structures. In the above method, the structural weak points of the rocks are removed by coating or filling the structural non-continuities in the interiors of the holes using a special material such as cement mortar, lime, and instant hardening agents as stemming materials for thereby maintaining a negative pressure condition, so that an effective rock destruction is achieved. The object with common rock conditions is not well destructed by the above method. Therefore, a certain special stemming material should be used in order to maintain a certain negative pressure condition (namely, sealed state). In addition, a certain hardening time is needed for thereby having an anti- pressure strength capable of satisfying the condition of negative pressure using a special stemming material. Therefore, a work time for destructing objects is increased, and a construction period is increased due to an inherent civil construction having a periodic work process, and a construction cost is increased. In a heavily jointed rock mass, even when a stemming material is used, it is impossible to maintain a negative pressure condition, so that a rock destruction effect is significantly decreased.
In the case of the above conventional art in which rocks are destructed using a vaporization expansion pressure using a non-nitrate metallic salt and metallic powder, it is needed to maintain a certain negative pressure condition (sealed state) in order to generate a ultra high pressure state. Therefore, a special stemming material such as cement mortar, instant hardening material, etc. is needed. In this case, even when a required negative pressure condition is met using a filling of stemming material, it is needed to maintain a high temperature for a vaporization expansion. Therefore, in this case, a high temperature heat is easily transferred to surrounding rocks, so that a loss of vaporization expansion pressure occurs, whereby a rock destruction effect is decreased.